American vintage 1875 watercolor painting young girls and mid 19th century buildings

Watercolor on paper, unsigned, undated but likely dating from the period 1865 to 1885, 15 3/4" by 11 3/8" inside the mat, (27 1/2" by 22 1/2" as framed), showing two young schoolgirls in the yard of a brick and wood shutters style mid nineteenth century home, such as would be found in Boston's Beacon Hill, or parts of New York City. There's a lot of skill in this drawing, and the artist was likely trained and probably could be found in reference books as a listed name, had he signed it. There's considerable but very even browning (oxidation) of the paper, the extent of this being most easily understood by looking at the thin edges which were protected by a mat (see photos). They are considerably lighter, tending more towards gray than brown/tan. However there's no foxing or moisture damage. There's a VERRRY light abrasion in sky above the building. At lower left edge, an edge tear has now become a completely separated area (update!). Ask for photo of that. The drawing of the young girls captures the youth of the period, and the way they dressed. If anyone could suggest an artist name on this one, feel free to contact me. This drawing was found near St. Augustine, Florida. SEE HUNDREDS OF OTHER WORKS NOW IN MY RUBY LANE SHOP.